A California man was sentenced to eight years in prison for identity theft after federal police GPS-tracked his phone and discovered a hard drive with over 300,000 victim profiles during a raid of his home.

Robert Delgado, 40, who lived in a Los Angeles suburb called Monterey Park, pleaded guilty earlier this year to conspiracy to commit bank fraud and was sentenced on Monday. At the time of his arrest in March 2011, Delgado had already been on parole for identity theft.

Court documents show Delgado was accused of obtaining credit card numbers, forging credit cards and government-issued ID sporting his (or a co-conspirator's) photograph, and using the identity documents to buy flat screen TVs, power tools, electronics, and jewelry. Those in turn would be sold for cash.

Eve Williams, a U.S. Postal Inspector, said she began the investigation after a victim of identity fraud contacted the Post Office and said that his mail delivery had been suspended and accounts had been fraudulently opened in his name.

With the help of an informant and some Internet searching, Williams found a Facebook page with Delgado's mobile phone number publicly listed. That same phone number, she learned from GE Money Bank, had made 350 calls to the company, even though Delgado didn't have an account there.

Delgado admitted in a May 2011 plea agreement that he obtained JC Penny credit card numbers from a co-conspirator and called JC Penny's merchant account line to learn which of the corresponding accounts had available credit. The JC Penny accounts were guaranteed by GE Money Bank.

Postal inspectors also said that video surveillance at a Lowe's store recorded Delgado and a co-conspirator using a fake credit card in October 2010.

Williams, the postal inspector, obtained a warrant from a federal judge to track Delgado's phone to shopping malls in southern California where fraudulent transactions took place. (Whether police are required to obtain a warrant or not for GPS tracking is still constitutionally unsettled terrain -- the U.S. Supreme Court will hear a case this fall that is likely to set the ground rules for this kind of surveillance.)

Credit cards from HSBC, Citibank, GE Money Bank, and Target National Bank were affected. It's still not clear how Delgado obtained the 300,000 profiles in the first place; the Postal Service says it's still investigating.

The maximum penalty for the charge of conspiracy to commit bank fraud (that is, identity theft) was 30 years. In addition to the prison term, Delgado was also sentenced to five years of supervised release.